Summer McKesson struggled to breathe for years. Doctors told her it was because her blood would not stop clotting – and they couldn’t figure out why.

A single clot alone can be lethal; but the recurring and unexplained clots that formed in McKesson’s heart and lungs were a medical mystery.

After multiple surgeries to remove clots and scar tissue, McKesson traveled to the Mayo Clinic, where she sat in a conference room while renowned physicians and specialists worked through her case on a whiteboard.

But even they were baffled.

“To hear that even they had never seen it before,” she told CNN through tears, “I came back (home) just crushed at that point.”

Desperate for answers, McKesson said she turned to 23andMe, hoping the DNA analysis service, which claims to offer insights into its clients’ genetic health history, might unlock some clues to her condition.

But her quest for answers would unearth a family secret – and a doctor’s decades-old deception that has ensnared multiple families across the country.

Ask your parents about Dr. Peete

McKesson never questioned her genetics – or considered 23andMe – until a team of surgeons performed an urgent, open-heart procedure in 2022 to remove clots from her heart and lungs.

As she recovered, McKesson said her surgeon dropped another bomb.

While operating, he’d noticed the connective tissue that supports her organs was stretchy and unusually fragile. He told her the complication – coupled with McKesson’s willowy build and Amazonian height – could be a sign of an inherited disorder called Marfan syndrome.

His suspicions were correct. A geneticist confirmed McKesson’s diagnosis, and said her clotting disorder was also genetic, which ushered in a host of lifelong health challenges.

Her heart would now need to be constantly monitored, and she will eventually need at least one more major heart surgery.

But the diagnosis was puzzling for another reason: both of her conditions are genetic and, as far as she knew, no one else in her family had them.

Summer McKesson recovering from surgery Courtesy Summer McKesson

Summer McKesson post surgery scar Courtesy Summer McKesson

McKesson, 43, said she didn’t have a full picture of her family’s health history because her father died when she was a teenager. So, she signed up for 23andMe, submitted a DNA sample, and waited.

The results arrived in her inbox in October 2023.

“I was just sitting on my couch after work, and kind of quickly pulled up the results on my phone,” McKesson recalled. At first, she said, she was curious to learn more about her family’s ethnic background.

“Growing up, I always was like … ‘I don’t look like any of y’all. No one has my nose. I’m a foot taller than everyone,’” she said, adding her family used to joke that she was adopted.

While there weren’t many surprises in her family’s ancestry, McKesson said when she navigated to the “family members” section of the site, she drew up short:

The test showed she had seven half-siblings.

“I just remember being shocked and my mind